1. Field of the Invention
The present invention relates to a disk controller. More particularly, it concerns a method and system for a high-reliable disk system to increase trouble resistivity and maintainability to partial defects on surfaces of recording media of a multiple of drives connected to a disk system.
2. Description of the Prior Art
Conventionally, as described in the IBM's manual GC 26-495-02, "Maintaining IBM Storage Subsystem Media," maintenance of a surface of a disk recording medium (hereinafter referred to as the inspection process) has been accomplished by way of a system software in a host computer or an external computer (hereinafter briefly referred to as the host) with use of read and write features of a disk controller. That is, the host directs the disk controller to read data on a current track, to assign an alternative track, to write the data of the current track to the alternative track, and to write to and read a test pattern from the current track. With this, the disk controller detects and reads defect position information on the surface of the recording medium, and writes the information onto the current track, and reads and rewrites the data saved on the alternative track to the current track.
In the prior method that the inspection process is made as the host feature, a series of processes for detecting the defect positions on the surface of the disk recording medium have to be executed as jobs of the host computer. This involves the disadvantage that the jobs temporarily occupy the CPU of the host computer which is resources of the host computer or the channel bus. In addition, a user has to manipulate for entering jobs for inspection process to the host computer. This involves the disadvantage of possible human errors that could cause troubles of disturbance to an online processing system of the host computer.